Arginine-supplemented enteral nutrition in critically ill diabetic and obese rats: A dose-ranging study evaluating nutritional status and macrophage function

Postoperative nutrition in the setting of enhanced recovery programmes

Patients undergoing major surgery for gastrointestinal cancer are at high risk of developing or worsening malnutrition and sarcopenia. In malnourished patients, preoperative nutritional support may not be sufficient and so postoperative support is advised. This narrative review addresses several aspects of postoperative nutritional care in the setting of enhanced recovery programmes. Early oral feeding, therapeutic diet, oral nutritional supplements, immunonutrition, and probiotics are discussed. When postoperative intake is insufficient, nutritional support favouring the enteral route is recommended. Whether this approach should use a nasojejunal tube or jejunostomy is still a matter of debate. In the setting of enhanced recovery programmes with early discharge, nutritional follow-up and care should be continued beyond the short time in hospital. In enhanced recovery programmes, the main specific aspects of nutrition are patient education, early oral intake, and post-discharge care. The other aspects do not differ from conventional care.

Comparison of enteral immunonutrition and enteral nutrition in patients undergoing gastric cancer surgery: a systematic review and meta-analysis of randomized, controlled trials

OBJECTIVE

Enteral immunonutrition is a nutritional intervention that has been studied in postoperative patients with gastric cancer, but its effectiveness is controversial. This study aimed to investigate the effects of enteral immunonutrition and enteral nutrition on immune function in patients who undergo gastric cancer surgery.

METHODS

We performed a systematic review and meta-analysis. A comprehensive search was conducted in PubMed, Embase, Cochrane, Web of Knowledge, and ClinicalTrials.gov from the inception of the review until 10 March 2023. Twelve studies were included for qualitative and quantitative analyses.

RESULTS

We studied 1124 patients, including 565 patients in the enteral immunonutrition group and 559 in the enteral nutrition (controls) group. All included randomized, controlled trials were high quality. CD4+ levels, lymphocytes, transferrin concentrations, and systemic inflammatory response syndrome were not significantly different between the enteral immunonutrition and enteral nutrition groups. However, CD8+, immunoglobulins G and M, and proalbumin concentrations, CD4+/CD8+, and infectious complications were significantly higher in the enteral immunonutrition group than in the enteral nutrition group. A sensitivity analysis showed consistent results after excluding each study. Begg's test showed no publication bias.

CONCLUSIONS

Enteral immunonutrition is an effective nutritional intervention that improves immune function in patients who have undergone gastric cancer surgery.

Kanserde Kaşeksi ve Beslenme

ABSTRACT Cachexia results from different combinations of metabolic variables and decreased food intake, including increased energy expenditure, excessive catabolism, and inflammations. Anorexia, asthenia, sarcopenia and anemia are clinical features of cachexia, and are effective in reducing the quality of life. The prevalence of cachexia in cancer patients is estimated to be 35%. There are 2 factors that cause the development of cachexia in cancer. The first is the disruption of the anabolic process. All types of cachexia are associated with anorexia, decreased oral intake, lack of movement, and accompanying endocrine changes. Factors such as early satiety, taste and tissue disorders, pain, psychological reasons, gastrointestinal system disorders, dry mouth are factors that contribute to weight loss by reducing oral intake. Secondly, it is the catabolic process caused by the tumor-derived factors and metabolic changes. Enteral and parenteral nutrition support improves the patient's nutritional status by increasing appetite and energy intake. A multidisciplinary team effort is required in prevention of cancer cachexia. The purpose of this review is to interpret the role of nutrition in cancer cachexia. Keywords: Cancer, cachexia, nutrition ÖZET Kaşeksi, artan enerji harcaması, aşırı katabolizma ve inflamasyonlar dahil olmak üzere, metabolik değişkenler ve azalan gıda alımının farklı kombinasyonları sonucu olarak ortaya çıkmaktadır. Anoreksiya, asteni, sarkopeni ve anemi kaşeksinin klinik özelliklerinden olup yaşam kalitesinin azalmasında etkili olmaktadır. Kanser hastalarında kaşeksi prevalansının %35 olduğu tahmin edilmektir. Kanserde kaşeksi gelişimine sebep olan 2 faktör bulunmaktadır; Birincisi anabolik sürecin bozulmasıdır. Bütün kaşeksi türlerinde anoreksiyle oral alımda azalma, hareket eksikliği ve eşlik eden endokrin değişimler mevcuttur. Erken doyma, tat ve doku rahatsızlıkları, ağrı, psikolojik sebepler, gastrointestinal sistem bozukluları, ağız kuruluğu gibi etmenler oral alımı azaltarak kilo kaybına katkı sağlayan faktörlerdir. İkinci olarak da tümör kaynaklı faktörler ve metabolik değişimlerin sebep olduğu katabolik süreçtir. Enteral ve parenteral beslenme desteği, iştah ve enerji alımında artış sağlayarak hastanın beslenme durumunda gelişme sağlamaktadır. Kanser kaşeksisinin önlenmesinde multidisipliner bir ekip çalışması gereklidir. Bu derlemenin amacı kanser kaşeksisinde beslenmenin rolünü yorumlamaktır. Anahtar kelimeler: Kanser, kaşeksi, beslenme

Effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy: A meta-analysis

We performed a meta‐analysis to evaluate the effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy. A systematic literature search up to November 2021 was done, and 10 studies included 1056 subjects with gastric cancer undergoing a total gastrectomy at the start of the study: 505 of them were provided with enteral immunonutrition, and 551 were enteral nutrition. They were reporting relationships about the effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy. We calculated the odds ratio (OR) or mean difference (MD) with 95% confidence intervals (CIs) to assess the effect of enteral immunonutrition compared with enteral nutrition on surgical wound infection, immune and inflammatory factors, serum proteins, and cellular immunity in subjects with gastric cancer undergoing a total gastrectomy using the dichotomous or contentious method with a random or fixed‐effect model. Enteral immunonutrition had no significant difference in the surgical wound infection (OR, 0.77; 95% CI, 0.50‐1.19, P = .24), the infectious complication (OR, 0.72; 95% CI, .48‐1.09, P = .13), the systemic inflammatory response syndrome (MD, ‐0.50; 95% CI, −1.40 to 0.39, P = .27), the CD8+ level (MD, 1.34; 95% CI, 0‐2.68, P = .05), the CD4+ level (MD, 1.21; 95% CI, −7.65 to 10.07, P = .79), the CD4‐CD8+ (MD, 0.55; 95% CI, 0‐1.10, P = .05), the lymphocyte (MD, −0.77; 95% CI, −1.87 to 0.33, P = .17), and the transferrin (MD, 0.03; 95% CI, −0.01 to 0.08, P = .14) compared with enteral nutrition in subjects with gastric cancer undergoing a total gastrectomy. However, enteral immunonutrition had significantly higher proalbumin (MD, 22.15; 95% CI, 3.57‐40.72, P = .02), IgM (MD, 0.47; 95% CI, 0.43‐0.50, P < .001), and IgG (MD, 1.98; 95% CI, 1.08‐2.89, P < .001) compared with enteral nutrition in subjects with gastric cancer undergoing a total gastrectomy. Enteral immunonutrition had no significant difference in the surgical wound infection, the infectious complication, the systemic inflammatory response syndrome, the CD8+ level, the CD4+ level, the CD4+/CD8+, the lymphocyte, and the transferrin, and had significantly higher proalbumin, IgM, and IgG compared with enteral nutrition in subjects with gastric cancer undergoing a total gastrectomy. Further studies are required to validate these findings or to affect the confidence level.

Effect of Enteral Immunonutrition on Immune, Inflammatory Markers and Nutritional Status in Gastric Cancer Patients Undergoing Gastrectomy: A Randomized Double-Blinded Controlled Trial

Backgrounds: Enteral immunonutrition (EIN) has received increasing attention, however, evidence on its immunomodulatory and anti-inflammatory function in gastric cancer patients undergoing gastrectomy is poorly investigated. Objectives of this study were to evaluate the effect of EIN on immune function, inflammation response and nutrition status when compared to standard enteral nutrition (SEN). Methods: Totally 124 gastric cancer patients after gastrectomy were randomized to receive early 5-days postoperative EIN (formula enriched with arginine, glutamine, omega-3 fatty acids and nucleotide), or SEN. The primary end-points were CD4⁺ T-cells, CD3⁺ T-cells as well as counts of CD4⁺/CD8⁺, IgG, IgM, and IgA levels. Second-points included white blood cell (WBC), C-reactive protein (CRP), procalcitonin (PCT), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) levels and nutritional index such as serum albumin, prealbumin, and transferrin concentration. Results: There existed significant difference in primary end-points between EIN group and SEN group. The proportion of CD4⁺ T-cells, CD3⁺ T-cells and the counts of CD4⁺/CD8⁺, IgG, IgM, and IgA were higher in EIN group eventually. Meanwhile, the level of WBC, CRP and TNF-α were significantly lower in EIN group finally. But there were no other significant differences in nutritional markers between two groups. Conclusion: Early postoperative EIN significantly improves immune function and inflammatory response in gastric cancer patients undergoing gastrectomy.

Mechanisms of obesity-induced metabolic and vascular dysfunctions

Obesity has reached epidemic proportions and its prevalence is climbing. Obesity is characterized by hypertrophied adipocytes with a dysregulated adipokine secretion profile, increased recruitment of inflammatory cells, and impaired metabolic homeostasis that eventually results in the development of systemic insulin resistance, a phenotype of type 2 diabetes. Nitric oxide synthase (NOS) is an enzyme that converts L-arginine to nitric oxide (NO), which functions to maintain vascular and adipocyte homeostasis. Arginase is a ureohydrolase enzyme that competes with NOS for L-arginine. Arginase activity/expression is upregulated in obesity, which results in diminished bioavailability of NO, impairing both adipocyte and vascular endothelial cell function. Given the emerging role of NO in the regulation of adipocyte physiology and metabolic capacity, this review explores the interplay between arginase and NO, and their effect on the development of metabolic disorders, cardiovascular diseases, and mitochondrial dysfunction in obesity. A comprehensive understanding of the mechanisms involved in the development of obesity-induced metabolic and vascular dysfunction is necessary for the identification of more effective and tailored therapeutic avenues for their prevention and treatment.

Enteral immunonutrition versus enteral nutrition for gastric cancer patients undergoing a total gastrectomy: a systematic review and meta-analysis

Background

Nutrition support is a common means for patients with gastric cancer, especially for those undergoing elective surgery. Recently, enteral immunonutrition (EIN) was increasingly found to be more effective than enteral nutrition (EN) in enhancing the host immunity and eventually improving the prognosis of gastric cancer patients undergoing gastrectomy. However, the results reported were not consistent. This meta-analysis aimed to assess the impact of EIN for patients with GC on biochemical, immune indices and clinical outcomes.

Methods

Four electronical databases (Medline, EMBASE, Scopus and Cochrane library) were used to search articles in peer-reviewed, English-language journals. Mean difference (MD), Relative risk (RR), or standard mean difference (SMD) with 95% confidence interval (CI) were calculated. Heterogeneity was assessed by Cochrane Q and I² statistic combined with corresponding P-value. The analysis was carried out with RevMan 5.3.

Results

Seven studies involving 583 patients were eligible for the pooled analysis. EIN, when beyond a 7-day time-frame post-operatively (D ≥ 7), increased level of CD4⁺ (SMD = 0.99; 95% CI, 0.65–1.33; P < 0.00001), CD4⁺/ CD8⁺ (SMD = 0.34; 95% CI, 0.02–0.67; P = 0.04), the IgM (SMD = 1.15; 95% CI, 0.11–2.20; P = 0.03), the IgG (SMD = 0.98; 95% CI, 0.55–1.42; P < 0.0001), the lymphocyte (SMD = 0.69; 95% CI, 0.32–1.06; P = 0.0003), and the proalbumin (SMD = 0.73; 95% CI, 0.33–1.14; P = 0.0004). However, those increased effects were not obvious within a 7-day time-frame post-operatively (D < 7). The levels of CD8⁺ and other serum proteins except proalbumin were not improved both on D ≥ 7 and D < 7. Clinical outcomes such as systemic inflammatory response syndrone (SIRS) (MD, - 0.89 days; 95% CI, - 1.40 to - 0.39; P = 0.005), and postoperative complications (RR, 0.29; 95% CI, 0.14–0.60; P = 0.001) were significantly reduced in EIN group. Pulmonary infection and length of hospitalization (LHS) were not improved no matter what time after surgery.

Conclusions

EIN was found to improve the cellular immunity, modulate inflammatory reaction and reduce postoperative complication for GC patients undergoing radical gastrointestinal surgery. Exclusion of grey literature and non-English language studies was the key limitation in this study.

Indications and contraindications for infusing specific amino acids (leucine, glutamine, arginine, citrulline, and taurine) in critical illness

PURPOSE OF REVIEW

The review assesses the utility of supplementing parenteral or enteral nutrition of ICU patients with each of five specific amino acids that display pharmacological properties. Specifying indications implies also stating contraindications.Combined supplementation of amino acids with ω3-fatty acids and/or trace elements (immune-enhancing diets) will not be considered in this review because these mixtures do not allow the role of amino acids in the effect (positive or negative) of the mixture to be isolated, and so cannot show whether or not supplementation of a given amino acid is indicated.

RECENT FINDINGS

After decades of unbridled use of glutamine (GLN) supplementation in critically ill patients, recent large trials have brought a note of caution, indicating for example that GLN should not be used in patients with multiple organ failure. Yet these large trials do not change the conclusions of recent meta-analyses. Arginine (ARG), as a single dietary supplement, is probably not harmful in critical illness, in particular in a situation of ARG deficiency syndrome with low nitric oxide production. Citrulline supplementation strongly improves microcirculation in animal models with gut injury, but clinical studies are lacking. Taurine has a potent protective effect against ischemic reperfusion injury.

SUMMARY

Amino acid-based pharmaconutrition has displayed familiar 'big project' stages: enthusiasm (citrulline and taurine), doubt (GLN), hunt for the guilty (ARG), and backpedalling (leucine). Progress in this field is very slow, and sometimes gives way to retreat, as demonstrated by recent large trials on GLN supplementation.

Mature coconut water exhibits antidiabetic and antithrombotic potential via L-arginine-nitric oxide pathway in alloxan induced diabetic rats

BACKGROUND

The aims of the present study were to assess whether the antidiabetic activity of mature coconut water (MCW) is mediated through L-arginine-nitric oxide pathway in diabetic rats, and to study the effects of MCW on blood coagulation.

METHODS

Diabetes was induced in male Sprague-Dawley rats by injecting them with alloxan (150 mg/kg body weight). MCW (4 mL/100 g body weight) and L-arginine (7.5 mg/100 g body weight) was given orally for 45 days. L-NAME was given at a dose of 0.5 mg/kg body weight. Concentrations of blood glucose, plasma insulin, glycosylated hemoglobin (HbA1c), L-arginine, urine volume and urinary creatinine levels, activity of nitric oxide synthase (NOS), and arginase as well as the abnormalities in hemostasis and thrombosis were measured in all the experimental groups.

RESULTS

Treatment with MCW and L-arginine reduced the concentration of blood glucose and HbA1c in diabetic rats. MCW and L-arginine treatment exhibited significant antithrombotic activity in diabetic rats, which was evident from the reduced levels of WBC, platelets, fibrin, and fibrinogen. MCW and L-arginine treatment prolonged the prothrombin time in diabetic rats and reduced the activity of Factor V. In addition to this, the activity of nitric oxide synthase, liver and plasma arginine content, and urinary nitrite were higher in MCW-treated diabetic rats whereas L-NAME treatment inhibited the beneficial effects induced by MCW and arginine.

CONCLUSIONS

The results clearly indicate that L-arginine is a major factor responsible for the antidiabetic and antithrombotic potential of coconut water, and is mediated through the L-arginine-nitric oxide pathway.

Meta-analysis is not enough: The critical role of pathophysiology in determining optimal care in clinical nutrition

Evidence based medicine has preferably been based on prospective randomized controlled trials (PRCT's) and subsequent meta-analyses in many fields including nutrition and metabolism. These meta-analyses often yield convincing, contradictory or no proof of effectiveness. Consequently recommendations and guidelines of varying validity and quality have been published, often failing to convince the medical, insurance and government worlds to support nutritional care. Causes for lack of adequate proof of effectiveness are manifold. Many studies and meta-analyses lacked pathophysiological depth in design and interpretation. Study populations were not homogenous and endpoints not always clearly defined. Patients were included not at nutritional risk, unlikely to benefit from nutritional intervention. Others received nutrients in excess of requirements or tolerance due to organ failure. To include all available studies in a meta-analysis, study quality and homogeneity were only assessed on the basis of formal study design and outcome rather than on patient characteristics. Consequently, some studies showed benefit but included patients suffering harm, other studies were negative but contained patients that benefited. Recommendations did not always emphasize these shortcomings, confusing the medical and nutritional community and creating the impression that nutritional support is not beneficial. Strong reliance on meta-analyses and guidelines shifts the focus of education from studying clinical and nutritional physiology to memorizing guidelines. To prevent or improve malnutrition more physiological knowledge should be acquired to personalize nutritional practices and to more correctly value and evaluate the evidence. This also applies to the design and interpretation of PRCT's and meta-analyses.

The crucial role of l-arginine in macrophage activation: What you need to know about it

Nowadays, it is well recognized that amino acids are powerful molecules responsible for regulatory control over fundamental cellular processes. However, our understanding of the signaling cascades involved in amino acid sensing in organisms, as well as signal initiation, is largely limited. This is also the case of semi-essential amino acid l-arginine, which has multiple metabolic fates, and it is considered as one of the most versatile amino acids. Recently, some new and important facts have been published considering the role of l-arginine in the regulation of inflammatory processes in several human and mouse models, mediated also via the regulation of macrophage activation. Therefore, this mini review focuses on the actual summarization of information about (i) l-arginine bioavailability in organism, (ii) l-arginine-dependent regulation of nitric oxide synthase expression and nitric oxide production, and importantly (iii) its role in the activation of intracellular signaling pathways and G-protein-coupled receptors in macrophages.

Perioperative immunonutrition in patients undergoing liver transplantation: a randomized double-blind trial

Preliminary work suggested that perioperative immunonutrition (IMN) enriched in n-3 fatty acids, arginine, and nucleotides may improve preoperative nutritional status, enhance postoperative recovery, and reduce postoperative infectious complications in patients undergoing liver transplantation (LT). The current study examined these outcomes in a double-blind, randomized, controlled trial. Patients wait-listed for LT (n = 120) were randomized to either supplemental (0.6 L/d) oral IMN or an isocaloric control (CON). Enteral IMN or CON was resumed postoperatively and continued for at least 5 days. The change in total body protein (TBP) measured by neutron activation from study entry until immediately prior to LT was the primary endpoint and TBP measurements were repeated 10, 30, 90, 180, and 360 days after LT. Infectious complications were recorded for the first 30 postoperative days. Nineteen patients died or were delisted prior to LT. Fifty-two IMN and 49 CON patients received supplemental nutrition for a median (range) 56 (0-480) and 65 (0-348) days, respectively. Preoperative changes in TBP were not significant (IMN: 0.06 ± 0.15 [SEM]; CON: 0.12 ± 0.10 kg). Compared to baseline, a 0.7 ± 0.2 kg loss of TBP was seen in both groups at 30 days after LT (P < 0.0001) and, at 360 days, TBP had not increased significantly (IMN: 0.08 ± 0.19 kg; CON: 0.26 ± 0.23 kg). Infectious complications occurred in 31 (60%) IMN and 28 (57%) CON patients (P = 0.84). The median (range) postoperative hospital stay was 10 (5-105) days for IMN and 10 (6-27) days for CON patients (P = 0.68).

CONCLUSION

In patients undergoing LT, perioperative IMN did not provide significant benefits in terms of preoperative nutritional status or postoperative outcome.

In vitro anti-inflammatory effects of citrulline on peritoneal macrophages in Zucker diabetic fatty rats

In type 2 diabetes (T2D) macrophage dysfunction increases susceptibility to infection and mortality. This may result from the associated decreased plasma concentration of arginine, an amino acid that plays an important role in immunity. In vitro, increasing arginine availability leads to an improvement in macrophage function; however, arginine supplementation in diabetic obese patients may be detrimental. The aim of the present study was to assess in vitro whether citrulline, an arginine precursor, could replace arginine in the regulation of macrophage function under a condition of diabetes and obesity. Peritoneal macrophages from diabetic obese or lean rats were incubated for 6 h in an arginine-free medium, in the presence of increasing citrulline concentrations (0·1, 0·5, 1 or 2 mmol/l). Cytokine and NO production was determined. Peritoneal macrophages from either lean or diabetic obese rats produced NO, and at higher levels in the cells from lean rats. In diabetic obese rats, TNF-α production decreased with increasing citrulline concentrations, but was higher than that in the cells from lean rats. In contrast, IL-6 production increased with increasing citrulline concentrations. The present experiment shows that citrulline is effectively used for NO production and regulates cytokine production in macrophages from diabetic obese rats. This effect warrants in vivo evaluation in T2D-related inflammation.